This invention generally relates to a method and system for monitoring a pressurized system. More particularly, the present invention relates to a method and system for monitoring a pressure relief device.
Pressure relief devices are commonly used to protect systems that contain a pressurized fluid from experiencing potentially hazardous over-pressure conditions.
The pressure relief devices are designed to activate, or open, when the pressure of the fluid within the system reaches a predetermined pressure limit that indicates an over-pressure condition for the particular system. The predetermined pressure limit is variable and depends upon the design considerations of the particular system.
The pressure relief devices, which may be, for example, rupture disks, pressure relief valves, safety valves, control valves, explosion panels, or other such devices, are connected to the system so that at least a portion of the pressure relief device is exposed to the fluid within the system. When the fluid reaches or exceeds the predetermined pressure limit, the force of the fluid on the pressure relief device acts on the pressure relief device to activate the pressure relief device, thereby creating an opening. Fluid may then escape from the system through the opening to relieve the over-pressure condition.
In some systems, it is important to closely monitor the system and the pressure relief device to determine, as quickly as possible, when the pressure relief device activates. Quick notification of the activation of the pressure relief device will allow an operator or automated system to respond to the over-pressure condition. The response taken will depend upon the particular system and may include: taking corrective action to remedy the cause of the over-pressure condition; triggering the implementation of additional safety functions; or providing notification of fluid release for system audit purposes.
In other systems, it is important to closely monitor the system and the pressure relief device to determine, as quickly as possible, when the pressure relief device exhibits leakage. Quick notification will allow an operator or automated system to respond to the leakage. The response taken will depend upon the particular system and may include: taking corrective action to remedy the cause of the over-pressure condition; triggering the implementation of additional safety functions; or providing notification of fluid release for system audit purposes.
Some pressure relief devices may include a sensor that indicates when the pressure relief device has activated. Some of these sensors include an electrical circuit. The electrical circuit is routed through the pressure relief device such that the opening of the pressure relief device interrupts the circuit. The interruption in the circuit senses that the pressure relief device has activated and that fluid is escaping from the system.
When the sensor determines that the pressure relief device has opened or exhibits leakage, this fact needs to be communicated to an operator or automated system who has the capability to react to the situation. The conventional sensor systems are typically hard-wired to a light, or other indicator, that is activated when the sensor identifies that the pressure relief device has functioned. The illumination of the light alerts the operator or automated system to the function of the pressure relief device. However, because the indicator is hard-wired, or directly connected to the sensor, there is significant cost to installation, especially for existing systems. There may be further inconvenience if the pressurized system is located in a remote location or in a remote part of a processing facility.
In light of the foregoing, there is a need for a method and system for monitoring a pressurized system that solves one or more of the problems set forth above.